Fig. 4

A Hypoxia inhibits the phosphorylation of RBM38-Ser195. A549 cells were exposure to hypoxia (1% O2) for 18, 24 h, or normoxia for 24 h, followed by WB. B Hypoxia inhibits eIF4E2-GSK3β binding. Cells were exposure to normal or hypoxia (1% O2) condition for 24 h. Then, cell extracts were subjected to Co-IP with anti-GSK3β antibody or IgG, followed by WB. C SPPIER assay showed L-Arginine inhibits eIF4E2-GSK3β interaction. Cells transiently expressed EGFP-eIF4E2-HOTag3-T2A-GSK3β-HOTag6, and then 2mM L-Arginine was added to the cells for 1 h. Scale bars, 1 μm. D L-Arginine inhibits the phosphorylation of RBM38- Ser195. Cells were mock-treated or treated with different concentrations of L-Arginine (0.5, 1, 2 mM) for 24 h and subjected to WB. E Hypoxia inhibits the phosphorylation of p53-Ser33, Ser46, Ser315 and the expression of TOPBP1. HCT116 (left) or p53-null HCT116 (right) cells were exposure to normoxia or hypoxia (1% O2) condition for 18 h, followed by WB with indicated antibodies. F Expression of eIF4E2 isoform A activates the phosphorylation of Rbm38-Ser195 in eIF4E2-KO HCT116 cells. Vectors expressing eIF4E2 isoform A with HA-tag were mock-transfected or transfected into eIF4E2-KO HCT116 cells for 48 h respectively, along with treatment with 5 μM G3-I or scramble peptide as indicated for 24 h, followed by WB.